Theodolite measuring systems were originally confined to use for surveying in which two theodolites 10 and 12 mounted on stands 14 and 18, respectively, as shown in FIG. 1 were positioned a known distance apart which constituted the baseline and at known relative heights to each other. Each theodolite was then pointed at a point 22 in space of unknown coordinates and then, by using triangulation and the pointing angle of the theodolites relative to the baseline, the coordinates of the point would be determined. Commercial systems incorporated a computer 20 to measure the angles and control the pointing of the theodolites. Over the past few years such systems have begun to find industrial applications. However, all such systems require the relative positions of the theodolites to first be established by measurement and, during measurement, the object and the theodolites must be stable. Moreover, these systems can only measure one point at a time.
A laser rangefinder has been incorporated into a theodolite to make a station that can measure both the angle and distance to a target. Thus, a single station thus arranged provides all the functionality of a 3-D measuring system but still suffers from the drawbacks mentioned above.
Accordingly, it is an object of the invention to provide an improved theodolite measuring system. It is a further object of the invention to provide a theodolite measuring system that can establish coordinates in space without the need to make physical measurements to establish a baseline reference. It is a further object of the invention to provide a three dimensional coordinate measuring system that permits movement of the theodolites during measurement.